Abstract Library

#4601 Pembrolizumab combined with cisplatin or carboplatin and etoposide in treatment naïve advanced Merkel cell carcinoma (MCC): The phase II PANDORA Trial

Introduction: MCC is a rare and aggressive skin neuroendocrine tumour with high metastatic potential and mortality. Therapeutic options in metastatic/unresectable MCC are based on immunotherapy or platinum-based chemotherapy. However, a subgroup of patients (pts) has primary immunoresistance disease, so it would be important discover active upfront combinations. PANDORA trial [NCT 06086288] is an open-label, multicentre, single-arm phase II trial evaluating the activity and safety of pembrolizumab (PEM) combined with platinum-based chemotherapy as 1st line treatment in pts with metastatic, unresectable or recurrence MCC. Supported in part by a research grant from Investigator-Initiated Studies Program of MSD.

Conference:

Presenting Author: Oldani S

Authors: Oldani S, Morano F, Cingarlini S, Di Giacomo A, Borghesani M,

Keywords: Pembrolizumab, clinical trial, Merkel cell carcinoma, chemio-immunotherapy,

#4546 Epigenetic exploration of mesenteric fibrosis indicates epigenetic disruption of DAXX is driving metastatic potential in small intestinal neuroendocrine tumours

Introduction: Up to 50% of patients diagnosed with small intestinal neuroendocrine tumours (SI-NETs) are affected by mesenteric fibrosis (MF) which has significant pathological effects and impacts patient mortality.

Conference:

Presenting Author: Webster A

Authors: Webster A, Martins M, Hodgetts H, Feelders R, Hofland L,

Keywords: DNA methylation, SI-NET, Mesenteric fibrosis, Epigenetics, Gene regulation, DAXX,

#4353 Familial inactivating glucagon receptor mutation resulting in pancreatic neuroendocrine tumours with metastatic potential, somatic MEN1 mutations, and a heterozygous phenotype

Introduction: Homozygous pathogenic glucagon receptor (GCGR) mutations cause a syndrome with pancreatic glucagon cell hyperplasia and neoplasia (GCHN) associated with Mahvash disease. This is an exceptionally rare autosomal recessive hereditary pancreatic neuroendocrine tumour (panNET) syndrome, with approximately ten cases documented in the literature.

Conference:

Presenting Author: Kuiper J

Authors: Kuiper J, de Herder W, Brahim Y, van Velthuysen M, Brosens L,

Keywords: glucagon receptor mutation, mahvash disease, glucagon cell hyperplasia and neoplasia, pancreatic neuroendocrine tumour, MEN1,

#4253 New insight in the environment immunephenotyping of gastroenteropancreatic neuroendocrine neoplasms: CD 90 expression

Introduction: Neuroendocrine neoplasms (NEN) represent a particular model of host-tumor interaction. CD90 (Thy-1) is a glycoprotein involved in cell–cell/cell–matrix interactions and is associated to stem phenotype and metastatic potential.

Conference:

Presenting Author:

Authors: Verrico M, Botticelli A, Feola T, Di Gioia C, Scagnoli S,

Keywords: cd 90, neuroendocrine neoplasm,

#4240 Plasma extracellular vesicles number and size distinguish patients with neuroendocrine neoplasms

Introduction: Neuroendocrine Neoplasms (NENs) are heterogeneous neoplasms, whose metastatic potential is challenging to predict. Extracellular vesicles (EVs) have been described as mediators of communication between the tumor cells and their microenvironment, driving the formation of metastatic niches.

Conference:

Presenting Author: Angelioudaki I

Authors: Angelioudaki I, Pantazatou V, Tzingounis A, Kataki A, Memos N,

Keywords: Extracellular vesicles, plasma, Gastroenteropancreatic NEN,